Thanks very much chaps, more to come soon, with a slight improvement in quality as the murk lifted and the sun came out.
Grant, most of the 'graininess' is due to the shots to date, apart from being taken in poor conditions, have been cropped and enlarged from small images in the center of the frame, as the subjects were, mostly, a long way away.
I used to always use two camera bodies when I was using 35mm film, for exactly that reason of not having to change lenses. When I changed to digital, I started off with the Fuji 'bridge' camera, then got the Nikon D3100 kit, which came with the Nikon 18-55mm lens, and a Sigma 70-300mm zoom lens.
I bought a Nikon 55-300mm lens, as I found the Sigma a tad slow on auto focus, for airshow work, and my hands won't allow me to use manual focus, which I'd prefer.
I then picked up the Nikon D80 at a great price, as a used, almost new body, and now use that with the 300mm Nikon lens, and to be honest, most ground shots, and nearly all static stuff, are done with the little Fuji, which is a great all round camera, relatively inexpensive, and a good way to add that second camera to your outfit.